Ptosis, the drooping of the upper eyelid, is a condition that may be congenital or acquired. In congenital ptosis the levator palpebrae superioris muscle that elevates the lid is either absent or imperfectly developed. Acquired ptosis is usually due to injury or disease of the nerves that control the movements of the levator muscle. Ptosis may further be classified as myogenic, aponeurotic, neurogenic, mechanical or traumatic.
In most cases, surgery will be required to correct a ptotic lid. The surgical treatment is specifically adapted to address the underlying pathological condition. The amount of levator function present generally determines which surgical procedure will be adopted. For example, in myogenic ptosis, levator aponeurosis advancement or levator muscle resection has proven to be effective. In congenital ptosis, the resection of the levator may be done either externally or internally.
The levator aponeurosis advancement or muscle resection procedure is only useful when there is some function of the levator muscle. When levator function is essentially absent, the eyelid must be elevated or raised in some other way. The most often performed procedure at the present time is known as the frontalis suspension operation. In this procedure, the eyelid is suspended from the frontalis so that the eyelid is opened when the patient lifts the brow using the frontalis muscle. The connection may be made utilizing tendon tissue from the leg of the patient or synthetic material developed for this purpose. While this procedure allows the patient to open the eyelid and therefore see from the eye, it suffers from a number of drawbacks. The patient must adapt to the unnatural, sometimes tiring and uncomfortable movement of raising the brow to raise the eyelid. Further, the extent to which the patient is able to raise the lid, varies from procedure to procedure. Essentially, the procedure restores some eyelid function but that function is not natural. Of course, as the brow must be raised to raise the lid, this procedure is also a cosmetic failure. Thus, a need is identified for an improved procedure.